1. Field of the Invention
The present invention is directed towards an ophthalmic surgical cassette and pump system. More specifically, the present application is directed to a venturi ophthalmic surgical cassette and pump.
2. Description of Related Art
Ophthalmic surgical cassettes for use with various pump systems, including venturi pumps are well known in the art. Such surgical cassettes, particularly for use with the venturi pump, typically include a rigid walled cassette that can be connected to irrigation/aspiration tubing. In turn, the tubing is typically attached to a surgical handpiece for use by a surgeon during eye surgery. The rigid walled cassettes then have a majority of an interior volume of a cassette or container that collects aspirant fluid and tissue flow from a surgical site for later disposal. Such cassettes may be disposable or reusable. Such rigid walled cassettes are typically held within a pump assembly and therefore, it is particularly important that such cassettes have a fluid level detection scheme to prevent the cassette from overflowing and leaking surgical fluids into the interior of the pump and creating a bio-hazard, as well as possibly damaging the pump.
There are known fluid level detection schemes, such as that found in U.S. Pat. No. 4,773,897, wherein a float ball is used within a defined chamber of the cassette. The float ball then floats with the increasing level of fluids within the cassette and eventually blocks the path between a lightsource and a photo-transistor, which combine to form a fluid level detector. Once the float ball blocks the path of light to the photo-detector, the system then triggers the pump to stop and aspiration ceases until the cassette is emptied. While such float ball schemes have been used for years and are reliable, over time the float balls become somewhat water logged and the precise amount of float from a ball can vary from ball-to-ball during manufacturing. Therefore, the precise level of fluids within a cassette is not consistently determined by such a float ball and light detector scheme.
It is common for pump cassettes to include aspiration and irrigation tubing attached to the cassette. This tubing typically has to be pulled off of mating barbs on the cassette when the cassette needs to be emptied. Pulling such tubing off the barbs can be somewhat difficult and time consuming and is not easily accomplished. Therefore, it would be desirable to have a collection cassette, wherein the majority of tubing does not have to be removed from its connections. This would speed-up surgery, and make it much more user friendly for operating room personnel to prepare the cassette for further surgery in a timely fashion.
Prior art surgical cassettes typically dump the fluid from the aspiration tube into the cassette at a position towards the rear of the cassette and away from the operator. During surgery, a surgical console typically has sensors and indicator icons and audible alerts for when aspiration flow is presumed to have ceased, while still applying a vacuum to the aspiration tubing. Such schemes generally are sufficient to allow safe operation of the surgical cassette. However, it would be desirable for an operator to easily see fluid flowing into the interior volume of the container of the cassette to provide easy and convenient visual feedback to the operator that aspiration fluid flow is present.
Typical prior art surgical cassettes are essentially a three-dimensional rectangle in shape. It would be desirable to provide some sort of alignment or insertion guides to assist the operator in properly inserting the cassette into its respective pump.
Therefore, there exists the need for an improved ophthalmic surgical cassette and system.